Self-adjusting railway brake



sept. 15, 1925. r 1,553,557

H. RMMERMANN SELF ADJUSTING RAILWAY BRAKE i Filed June 28. 1924 Patented Sept. l5, 1925.

UNITED `STATES HEINRICH RMMERMANN, OF HALLE-ON-THE-SAALE, GERMANY.

SELF-ADJUSTING RAILWAY BRAKE.

Application mea :une 2a, 1924. Serin No. 722,983.

To r/ZZ whom t may concern.:

Be it known that I, Hamelen RMMER- MANN, a citizen of the German Republic, residing at Halle-on-the-Saale, Germany, have invented certain Improvements in Self- Adjusting Railway Brakes, of which the following is a speciiication.

rI'his invention relates to a brake for railway vehicles and of the kind in which the brake. shoe holder is adapted to adjust itself automatically to its correct position relative to the wheel, and the invention consists in the provision of a. shoe controlling stay carrying a toothed rack whereby it engages, under spring pressure, a rigidly held, correspondingly toothed supporting member so that, while it will yield to an adjusting .tendency of the brake shoe when thel latter is applied, the shoe will beretained in the readjusted position by the co-operation of j the spring with the rack.

Figs. .l and 2 of the accompanying drawings represent views at right angles of the device according to one form of' construction,

Fig. 3 is a perspective` view of the stay,

Fig. 4, a side view of a modified construction of the device, and

Fig. 5, side view of another modification.

The brake shoe holder a is pivotally adjustable about a. shaft 0 which is suspended in hangers 7c, the brake being applied by means of a traction rod or rods p in the usual manner.

According to the invention the angular position of the shoe holder is controlled by means of a stay carrying a toothed rack f, the latter Ibeing applied by spring pressure to a rigidly held, correspondingly toothed supporting member which, by engagement with the teeth of the rack, retains the brake shoe in whatever position it may assume during its application to the wheel. rlhus, if the load of the wagon should be varied, the first application of the brakes causes the racks f to slip on the supporting members g until the position of the respective brake shoes has been readjusted, whereupon the shoes will be retained in the new position.

Apart from the rack f, the stay may be composed simply of a spring formed of a doubled wire as shown in Fig. 3. The ends e of the wire are passed longitudinally through the rack f and secured to the latter,

and coils Z9, formed on the wire members, are engaged to a bolt g on the shoe holder al, as shown 1n Fig. 2, while the doubled end c of the spring is placed in a supporting notch el formed on the 'back of the holder. The rack f will thus be forced upwards against the supporting member g which is exchangeablyl heldl in a fork formed by a bracket it and an arm z' which latter is rigidly secured to the shaft o. One of the hangers 7s is curved to make room for the bracket 71., as shown in Fig. 2.

While in the construction shown in Figs. l and 2, the shoe controlling device is applied to the upper end of the shoe holder, it may, if more convenient, be applied to the lower end of the same, as shown in Fig. 4. The supporting member g is here held in a fork 7i. which depends from the shaft 0.

In a. further modification, which is shown in Fig. 5, the stay is composed of a rod Z which is pivoted to the shoe holder a and which carries the rack The supporting member g is arranged detachably in a fork z. as in the previous construction, but the spring action is obtained by means of a separate coil spring n which is arranged in a casing m secured to the fork h. yThe spring n bears against the rack f through the medium of a plunger fr and yields under the adjusting movements of the rack.

I claim:

In a brake for railway vehicles, the combination with a pivotally supported brake shoe holder, of a spring comprising a coil and two arm diverging fromsaid coil, said spring being connected by means of the coil to. the brake shoe holder so that one arm abuts against the latter and so that the other arm is capable of angular deflection, a toothed rack secured to the free arm of the spring, a. rigidly supported fork, and a toothed supporting member held by said fork as an abutment for the spring arm, the

support being adapted to oppose longitudinal as well as angular deflection of the spring arm by engagement with the rack, the rack being adapted to slip under adjusting movements of the shoe holder on the appli cation of the brake and then to retain the holder in readjusted position.

HEINRICH RMMERMANN. 

